Managing Soil Organic Matter and Salinity by Crop Cultivation in Saemangeum Reclaimed Tidal Land

Creating grasslands and cultivating forage crops on reclaimed tidal land in winter and early spring can contribute to improving soil physicochemical properties, reducing fine dust, and increasing feed self-sufficiency. Ryegrasses that adapt well to reclaimed land include tall fescue (Festuca arundinacea Schreb.) and Italian ryegrass (Lolium multiflorum Lam.), which are a cool-season perennial and a winter annual, respectively. To evaluate the salt uptake by winter crops and the soil desalinization, tall fescue and Italian ryegrass were grown twice for 3 years on Saemangeum reclaimed tidal land. The nutrient uptake and dry matter yield of crops were low in reclaimed tidal land compared to inland agricultural land, reflecting the nutrient-poor condition of the reclaimed tidal land. The crops removed 6.4 -10.3 kg ha -1 , 9.8 -12.5 kg ha -1 , and 4.1 -12.2 kg ha -1 for Ca, Mg, and Na per winter cultivation, respectively. Soil salinity significantly (P < 0.05) decreased in Italian ryegrass cultivation plot compared with control and tall fescue cultivation plots, reflecting salt removal by Italian ryegrass which was higher in salt uptake than tall fescue. These results suggest that creating grassland and cultivating forage crops on reclaimed tidal land in winter and early spring can contribute to soil desalinization along with the supply of forage containing high concentrations of minerals.

Section: Introductionunclassified

Salt Removal from Soil by Winter and Spring Cultivation of Tall Fescue and Italian Ryegrass in Saemangeum Reclaimed Tidal Land

Yun¹,

Kwak²,

Choi

et al. 2021

“…지속적인 농지면적 감소와 정부의 간척지 이용 종합계획 발표 (MAFRA, 2019) 등으로 간척지 논을 벼 재배 외의 밭작물 재배에 이용하는 농지범용화에 대한 연구가 활발히 진행되어왔으며, 간척지에서 사료작물 등의 타 작물 재배 연구가 증가하고 있다 (KREI, 2014;Bae et al, 2018). 이와 함께 간척지에서의 밭작물 생산량 및 자급률 향상을 위한 노력도 진행되고 있으나 (Bae et al, 2015;Ryu et al, 2016;Lee et al, 2020) 해안이나 강 하구 등 평탄한 저지대에 주 로 위치하는 간척지 특성상 높은 지하수위와 배수불량에 의한 통기 부족으로 습해 발생 위험성이 높다 (Sohn et al, 2009b).…”

Section: Introductionunclassified

Changes in Ridge Height and Maize Growth with Various Conservation Treatments Affected by Rainfall Characteristics in Saemangeum Reclaimed Land

Lee¹,

Jung²,

Lee³

et al. 2021

It is important to form and maintain ridges for air permeability within the upland crop root zone in Saemangeum reclaimed land with poor drainage. The ridge in the area, however, is difficult to be maintained due to high content of sand and silt, which are susceptible to water erosion. This study was conducted to investigate the reduction in the height of the ridge and maize growth as affected by rainfall characteristics through the application of ridge maintenance technology under maize cultivation in Saemangeum reclaimed land. Four treatments were examined: control, ridge covered by residue (RR), vegetation in furrow (VF), and RR + VF. Maize was Kwangpyeongok. The rainfall erosivity factor to compare the rainfall characteristics affecting changes in the height of the ridge was greater at 2,653.5 MJ mm ha -1 hr -1 in the 2nd year than that at 505.8 MJ mm ha -1 hr -1 in the 1st year. No significant difference in the decrease of ridge height (DRH) was found between treatments, but the DRH in 2nd year (8.5 cm) was larger than that in the 1st year (6.6 cm) with the stronger rainfall erosivity. The soil erodibility factor of the tested soil was 0.587 Mg hr MJ -1 mm -1 greater than the national average of 0.027 Mg hr MJ -1 mm -1 . The DRH had a negative relationships with fresh weight of maize implying that reduced ridges provided less functionality for plant growth. Therefore, a variety of conservation treatment is supposed to be studied to maintain ridges for arable lands in Saemangeum.

“…반면 Mg과 Na 등은 토양 물리성 개선에 따른 토양 배출이 증가하여 큰 폭으로 감소하였다 (Table2). 이는 새만금과 이집트 간척지에서 유 기물 투입시 Na 등이 감소한다는 보고와 일치하였다(El-Shakweer et al, 1998;Bae et al, 2018).…”

unclassified

Annual Changes in Soil Physicochemical Properties and Kenaf (Hibiscus cannabinus L.) Growth When Returning Grown Kenaf as Organic Matter in Reclaimed Land

Kang¹,

Lee²,

Choi³

et al. 2023

This experiment was conducted to confirm the efficiency of introducing natural organic matter, crushed kenaf (Hibiscus cannabinus L.), which could lead to soil physicochemical improvement and crop growth improvement in reclaimed land. The plant height of economical crop kenaf after adding crushed kenaf per 3,000 kg 10a -1 as organic matter in 2020 was 219.5 cm. This was 7% less growth than the kenaf grown in standard fertilization, and 13.4% higher than the kenaf grown under in natural non-managed state without fertilization. The kenaf yield in the first year of organic matter treatment in non-developed reclaimed land was 3,215 kg 10a -1 which was 14.7% higher compared to that of under in natural non-managed state without fertilization and 83.9% yield of standard fertilization treatment. However, in the second year of cultivation, the growth and yield of treated with crushed kenaf as an organic matter were increased significantly. The main reason is that enough time was given for the decomposition of the input crushed kenaf, and the effect of kenaf cultivation as a crop on improving the soil environment was clearly appeared. So, the plant height in the second year of kenaf treated with crushed kenaf as an organic matter was 320.9 cm, which was 46.2% higher than that in the first year. In addition, yield also increased significantly, reaching 5,916 kg 10a -1 , an 84% higher compared to that of the first year. This rate of yield increase was larger than 15% of in natural non-managed state without fertilization or 33% of standard fertilization treatment, which showed that using kenaf as an organic matter was much more effective in improving the soil environment of reclaimed land and improving crop growth and yield.